Apparatus for making coffee



y 9 1946. M. N. STATES 2,403,691

APPARATUS FOR MAKING COFFEE Original Filed Dec. 16, 1939 k gzz'zg Patented July 9, 1946 APPARATUS FOR MAKING COFFEE Marshall N. States, Evanston, Ill., assignor to Robert C. Brown, Jr.,

trustee Highland Park, 111., as

Original application December 16, 1939, Serial N 0. 309,585. Divided and this application October ,1, 1943, Serial No. 504,553

' 7 Claims. 1

This invention relates to an apparatus for preparing coffee and similar beverages.

It has been well-known for years that at least some of the substances providing coffee withits characteristic flavor and aroma are volatile "in nature and subject to undesirable changes if exposed to air for any considerable period of time. Manufacturers, recognizing this fact, have exercised great care in packing their cofiee to insure its arrival in proper condition. However, even when properly prepared coffees are used, coffee brewers now in use are usually unable to retain in the beverage the full value of flavor and aroma contained in the coffee itself, as they expose the solution containing the aroma giving and flavoring substances to the air at elevated temperatures for considerable periods of time, thereby boiling off or evaporating the materials most desirable in the finished product. v

Therefore, an object of this invention is to provide a brewing apparatus whereby coffee and similar beverages may be prepared without substantial loss of flavoring and aroma imparting substances.

Another object is to provide an apparatus suitable for use in my process in which any reasonable amount of beverage may be prepared regardless of the capacity of the container used.

Further objects and advantages of my invention will become apparent from the following de:

through the valve to It by means of which the valve plunger may be manually raised from its seat to release a vacuum formed in the container H. A longitudinal passageway I9 is provided through thestopper l2 in which the valve [3 is firmly positioned. A handle may be attached to the container for convenience in dispensing.

The container H may be of glass or other suitable material, and is provided with a neck of suitable diameter, flaring outwardly at the lip to aid in pouring- It may be in; the form of a carafe or decanterhaving'a globe-like container portion and an'elongated neck opening, whereby the air scription and the accompanying drawing, in g which v Fig. l is a vertical section of my preferre form of coffee brewer; V V

Fig. 2 is an enlarged vertical section of a slightly modified form of stopper; and r Fig. 3 illustrates another form of stopper.

For the purpose of illustration the followingdescription of my apparatus will be limited to the preparation of coffee, but it is to be understood that the same apparatus is equally adapt able to the preparation of other similar beverages.

Referring to Fig. 1, my preferred form of coffee brewer consists of a container II, which may be in the form of a carafe or decanter, fitted with a stopper l 2, which contains a valve I3 comprising a tubular valve body l4, the-lower portion of which is constricted, a valve plunger l5 operating within the valve body and'seating-itself in the constricted portion thereof, a valve top I6 fltting flnmly into, or around, the valve body l4 in which is provided a port or ports I! and an opening through which a valve stem [8 projects,

and avalve stem I8 connected to the valve plunger [5 and projecting beyond the valve bod; I4

is readily displaced by vapor and steam when heat is'applied to the vessel. By means of this arrangement it .isonly necessary to bring the water to a boil and then remove the vessel from v .the source of heat. The vessel is sealed imme- 20 diately before it is removed, and. the brewing is efiected a partial vacuum formed by the condensation of the vapor and steam. The material of the container II should be moderately resistant to thermal. shock, and sufficiently strong to resist atmosphericpressure when the interior of the container is substantially below atmospheric pressure. V

Thestopper l2 fits into the neck of the container l with sufiicient-tightness to prevent the leakage of air into the container, and is preferably made of high-grade natural or synthetic rubber compounded to resist oxidation and aging. One or more passageways [9 are provided through the stopper l 2 connecting the interior of the container ll with the atmosphere. For the purpose of illustration only one such passageway is shown in the drawing. l r

The valve I3 is preferably of brass or other metal which may be plated with chromium, cadmium, or nickel, if desired, and'is incorporated in the passageway 19 where it is maintained normally in its closed position, preferably by gravity. neck of the container II and heat is'applied to the container and its-c0ntents, the valve l3 operates to allow the release of the pressure developed within the container, as the pressure is transmitted through the passageway Hi to the base of the valve plunger I 5, forcing it, with its stem l8, upward, thereby allowing the displaced air and some vapor to escape through the port or ports 11. The valve I3 will assume a lower temperature than the escaping vapors, due to its higher heat conductivity and exposure to air, and therefore acts as a condenser. The droplets When the stopper I2 is placed in the c of condensate remaining in the valve form a liquid seal when the valve assumes the closed position, thereby eliminating the necessity of carefully machining the valve plunger and seat. When a vacuum is developed within the container H by the pressure of the atmosphere, it forces the valve plunger l5 firmlyinto its seat, and so prevents the entrance of air into the container. placed in the valve top 16, as shown in Fig. 1, rather than through the valve body, as shown in Fig. 2.

If desired, a stopper of the type illustrated in Fig. 3 may be used, in which case a passageway 2| is provided through the stopper 22 connecting the interior of the container llwith the interior of the stopper cap 23, to which air has free acces through openings 24. A valve 25 is provided to seal the passageway 2| under normal conditions, but is capable of release, either manually, as by lifting the lugs or projections 26, or by an excess of pressure formed within the container ll.

The stopper cap 23 may befastened to the stopper 22 in any desired manner, preferably by means of the inwardly extending flange portion 21 of the cap 23', on the inner side of which is provided projections or teeth 28 adapted to engage with corresponding indentations 29 properly positioned in the underside of an outwardly extending flange 30 of the stopper 22.

The valve 25 is held against the passageway 2| by means of springs 3! which may be integral with the valve. The action of these springs against the stopper cap 23 not only firmly seats the valve 25 against the passageway 2|, but also serves to fasten the cap 2-3 more'firmly to the stopper by forcing the projections 28 into the corresponding indentations 29 on the underside of the stopper flange 30. The portion of the valve 25 that seals the passageway 2| is preferably depressed somewhat below the normal plane of the valve to insure a more satisfactory seal. The lugs 26 are a part of the valve 25 and extend through the openings 24 in the cap By raising these lugs 26, or any one of them,

23. the valve 25 is lifted from the passageway 2| and air is allowed. free access to the interior of the container ll. As a vacuum is developed within the container I I, during my process, when this type of valve is used, I prefer to constrict the passageway 2| at its upper terminal portion,

as shown at 32, thereby facilitating the release reducing the possibility of of the valve 25 and leakage.

Regardless of the type of valve used, I prefer to provide means for manually releasing the valve to destroy the vacuum formed in the container, as by raising the valve stem l8 or the lugs 28 to open the passageway into the container, for unless this is done the stopper is often quite difficult to remove.

In the use of the brewing apparatus the desired amount of ground coffee beans is placed in the container l I, and then is added theproper amount of water, either hot or cold, but not to exceed 90 percent of the capacity of the container. The stopper assembly is then inserted in the neck of the container l I and the latter heated to boiling, after which it is removed If desired the outlet ports Il may be r solution to move through the passageway l9 into the interior of the valve I3, where at least a portion of the vapors are condensed, the excess escaping through the port or ports l'l. When removed from the source of heat, the pressure within the container rapidly decreases to a point where it ,is insufficient to maintain the valve plunger l5 in its open position. When this point is reached the plunger l5 and stem l8 fall into the closed position on the valve seat in the constricted portion of the valve body 14, and the condensate remaining in the valve forms a liquid seal over-and around the valve plunger l5, efifectively preventing the entrance of air into the container. As the container II and. it contents cool, the pressure within the container is rapidly loweredbelow atmospheric due to the condensation of the vapor or steam. This reduced presany small coffee particles remaining suspended of the flask. If, however, the chaf,'or similar process of extraction is not completely undersure, in combination with the heat of the water, brings the aromatic and flavoring substances in the ground coffee rapidly to the surface of the particles and into solution.

The container is maintained in a sealed condition for about five minutes, or until the action or movement of the coffee particles has ceased. The vacuum is then released by raising the valve stem I8 which opens the passageway [9 into the container. As this equalizes the interior and exterior pressures, the stopper may then be easily removed; When the vacuum is released in the liquid will become saturated and'immediately sink to the bottom, a strainer or filter not being needed as all the coffee particles are completely saturated and will cling to the bottom foreign material, is present, it'may not become saturated, so a filter may be employed; but it is not necessary if a good grade of cofiee is used.

As the precise reaction occurring during this stood, I do not wish to be confined by any theory herein advanced, but for clarity of'illustration I will explain the reaction to the best of my knowledge and belief. The aromatic and flavoring'ingredients, which may be oil, esters, or other compounds, are more or less Water soluble materials held within the cells and body of the coffee particles. To allow water to penetrate the interior cells and dissolve these ingredients it is necessary to release in some manner the entrapped air withinthe cells.

The entrapped air is, of course, at normal atmospheric pressure, so unless some force is applied there is no tendency for this air to move out of the cells. By'reducing the pressure against this entrapped air the balance of pressures within and without the cells is disturbed, so the air will, by its own pressure, move outwardly until the internal pressure balances the external; This action is augmented by the application of heat from the source of heat and allowed to cool.

into the open position, allowing the air in, the

container and vapors arising from the heated to the air within the cells. When the entrapped air has been released the water may enter and dissolve the desired aromatic and flavoring ingredients.- 7

Upon release of the vacuum the. reverse of this process occurs, as the external pressure is then greater than that of theair remaining in the cells; so the water is forced into the cells until the external and internal pressures are again equal,

The air drawn from the coffee particles may contain certain vapors or other substances imparting'flavor and aroma to the beverage, Any" portion of theseLvapors not dissolved by the water while .the air bubble is rising to, the surface. is re 'tained in contact with the solution after release, as the container is closed. Likewise, any dissolved the bottom they cannot be re-suspendedeven by continued shaking.

From the foregoing description the advantages incident to the use of my apparatus are more or less obvious. The parts are'few in number and easily cleaned. Substantially all of the aromatic and flavoring substances'in the coffee are retained as the container is sealed against their escape during practically the entire operation of the apparatus. Furthermore, the minimum amount of beverage that may be prepared is not limited by the capacity of the container, as the coffee and water are in direct contact at all times; The harsh and unpleasant flavor sometimes present in coffee that has been overboiled is not present,

as the continued boiling which is necessary to extract these substances is neither necessary nor desirable in the use of my apparatus.

It is not necessary that the coffee be allowed to cool extensively, as a relatively small drop in temperature produces a marked reduction in pressure; for example, as the liquid cools from 100 C. to 90 C., the pressure is reduced about and if cooled further to 80 C. the pressure is re-,

duced about 50%. When making large quantities of coffee other structures for producing a vacuum may be used, such as an ordinary aspirator or.

vacuum pump connected to the upper part of the container or stopper in any desired manner; but this construction is not as desirable for ordinary household use as that herein described due to the extra equipment required.

This application is a division of my application Serial No. 309,585, filed December 16, 1939, now issued as Patent 2,338,140.

The foregoing description illustrates only the preferred embodiment of my apparatus, which is obviously capable of considerable modification. In the use of the apparatus, for example, the stopper may be inserted shortly before the container is removed from the source of heat, or the coffee particles may be added after the water is heated, or heated water may be added to the coffee particles, or the time required for the process may be reduced by rapidly cooling the container after the stopper has been inserted. The apparatus is capable of wide variation, as the shape of the container is not primarily important. The stopper may be used either with or without a valve or valves, it being essential, however, that the stopper be constructed to produce an air-tight seal across or within the neck of the container. I do not, therefore, wish to limit myself to the specific embodiment of my invention hereinbefore disclosed except as defined by the appended claims.

I claim as my invention:

1. An apparatus for preparing coffee beverage from a content of coffee and water, comprising a 1 container of globular-like form of a material to withstand the local application of iii tense heat .through and constituting the sole passage between the exterior and interior of said container, a stopper for said passage, said stopper having a passageway therethrough, and a valve for said passageway biased to a closed position for nor m'ally preventing the entrance of air tosaid container but permitting air and steam to escape from :said container when said water is boiled within said container whereby the valve will close automatically at the end of a boiling period to produce a partial vacuum insaid container for steeping said coffee when said container cools sufficiently to condense the steam therein.

2. An apparatus for preparing potable coffee comprising a carafe-shaped container of .a material to withstand the local application of intense heat for raising the temperature of the liquid therein consisting ofabody portion and a neck of small diameter extending upwardly therefrom and having a single passage extending longitudinally thereof and constituting the sole intake and discharge passage to and from said container, a resilient stopper for said passage, a bore extending longitudinally of said stepper, .a discharge valve for said passage for perby said stopper and the water heated to the boiling'point, air and steam will escape from said container and when thereafter the container is removed from the source of heat, the ground coffee will be steeped under a partial vacuum during the cooling of said container.

3. An apparatus for preparing coffee, comprising a single container of globular-like form provided with an elongated upwardly extending neck having a passage extending upwardly therethrough and constituting the sole passage between the exterior and interior of said container, a stopper for said passage, said stopper having a passageway therethrough, a valve for said passageway biased to closed position for normally preventing the entrance of air to said container but permitting air and steam to escape from said container when a liquid is boiled within said container whereby a partial vacuum will be produced in said container forsteeping said coffee when said container cools sufiiciently to condense the steam therein, and means for manually manipulating said valve for breaking said partial vacuum.

4. An apparatus for preparing coffee or similar beverages by a process wherein a partial vacuum is employed to aid in the extraction of flavoring ingredients from vegetable materials comprising a single corrosion resistant container for the liquid and solids involved adapted to withstand at-.

mospheric pressure, said container comprising a last-named passage for permitting the passage of air and steam from said container-when heat is applied to the container.

5. An apparatus for preparing coffee or similar beverages by a process wherein a partial vacuum is employed to aid in the extraction of flavorin ingredients from vegetable materials by the withdrawal of air from the minute interstices of the vegetable material during liquid submersion of the material comprising a single container for the liquid and solids involved made of a material to withstand the local application of intense heat for raising the temperature of liquid therein to substantially the boiling point, said container having a single passage between the interior thereof and the atmosphere, and a check valve for sealing said passage to automatically allow the escape of substantially all air from within the container and to prevent the entrance of external air, said automatic valve being manually releasable.

6. An apparatus for preparing coffee or similar beverages by a process wherein a partial vacuum is employed to aid in the extraction of flavoring ingredients from vegetable materials by the withdrawal of air from the minute interstices of the vegetable material during liquid submersion of the material comprising a container to hold both the liquid and solids involved, said container having an upwardly extending neck with a narrow passage constituting the sole opening to 8 the atmosphere; and a check valve limiting fluid flow through said passage to outflow for automatically permitting the substantially free effiux and preventing the influx of air through said passageway, said means being capable of manual release.

'7. An apparatus for preparing coffee or similar beverages by a process wherein a partial vacuum is employed to aid in the extraction of flavoring ingredients from vegetable materials submerged in heated liquid by the withdrawal of air from the minute interstices of the submerged material comprising a heat-resistant container with an opening for pouring the finished beverage, a stopper for said opening, said stopper having a passageway therethrough for the exit of air and vapor, a check valve for said passageway to substantially prevent the inflow of air whereby a partial vacuum will be produced in the container for steeping the vegetable material when said container cools sufiiciently to condense the steam therein after the generation of the steam has substantially replaced air within the container, said check valve being located within said passageway substantially below the level of the outer end of the passageway whereby condensate formed by escaping vapors may increase the sealing effectiveness of the check valve, and means extending to the exterior of said stopper from said Valve for manual release of the check valve MARSHALL N. STATES. 

